TY - JOUR

T1 - Mechanical revision following pedicle subtraction osteotomy

T2 - a competing risk survival analysis in 171 consecutive adult spinal deformity patients

AU - Bari, Tanvir Johanning

AU - Hallager, Dennis Winge

AU - Hansen, Lars Valentin

AU - Dahl, Benny

AU - Gehrchen, Martin

N1 - Publisher Copyright: © 2020, Scoliosis Research Society.

PY - 2021

Y1 - 2021

N2 - Study design: Retrospective study. Objective: To report the incidence of revision surgery due to mechanical failure following pedicle subtraction osteotomy (PSO) in adult spinal deformity (ASD) patients. Summary of background data: PSO allow major surgical correction of ASD, although; the risk of mechanical complications remains considerable. Previous reports have been based on smaller cohorts or multicenter databases and none have utilized competing risk (CR) survival analysis. Methods: All ASD patients undergoing PSO surgery from 2010 to 2015 at a single, tertiary institution were included. Demographics, long standing radiographs as well as intra- and postoperative complications were registered for all. A CR-model was used to estimate the incidence of revision surgery due to mechanical failure and two predefined multivariable models were used to assess radiographic prediction of failure and reported as odds ratios (OR) with 95% confidence intervals (95% CI). Results: A total of 171 patients were included with 2-year follow-up available for 91% (mean [IQR]: 35 [24–50] months). Mechanical failure occurred in 111 cases (65%) at any time in follow-up, the most frequent being rod breakage affecting 81 patients (47%). Cumulative incidence of revision surgery due to mechanical failure was estimated to 34% at 2 years and 58% at 5 years. A multivariable proportional odds model with death as competing risk showed significantly increased odds of revision with fusion to the sacrum (OR: 5.42; 95% CI 1.89–15.49) and preoperative pelvic tilt (PT) > 20° (OR: 2.41; 95% CI 1.13–5.16). History of previous surgery, number of instrumented vertebra, as well as postoperative SRS-Schwab modifiers and Global Alignment and Proportion score were not associated with significant effects on odds of revision. Conclusions: In a consecutive single-center cohort of patients undergoing PSO for ASD, we found an estimated incidence of revision surgery due to mechanical failure of 34% 2 years postoperatively. Fusion to the sacrum and preoperative PT > 20° were associated with elevated risks of revision. Level of evidence: Prognostic III.

AB - Study design: Retrospective study. Objective: To report the incidence of revision surgery due to mechanical failure following pedicle subtraction osteotomy (PSO) in adult spinal deformity (ASD) patients. Summary of background data: PSO allow major surgical correction of ASD, although; the risk of mechanical complications remains considerable. Previous reports have been based on smaller cohorts or multicenter databases and none have utilized competing risk (CR) survival analysis. Methods: All ASD patients undergoing PSO surgery from 2010 to 2015 at a single, tertiary institution were included. Demographics, long standing radiographs as well as intra- and postoperative complications were registered for all. A CR-model was used to estimate the incidence of revision surgery due to mechanical failure and two predefined multivariable models were used to assess radiographic prediction of failure and reported as odds ratios (OR) with 95% confidence intervals (95% CI). Results: A total of 171 patients were included with 2-year follow-up available for 91% (mean [IQR]: 35 [24–50] months). Mechanical failure occurred in 111 cases (65%) at any time in follow-up, the most frequent being rod breakage affecting 81 patients (47%). Cumulative incidence of revision surgery due to mechanical failure was estimated to 34% at 2 years and 58% at 5 years. A multivariable proportional odds model with death as competing risk showed significantly increased odds of revision with fusion to the sacrum (OR: 5.42; 95% CI 1.89–15.49) and preoperative pelvic tilt (PT) > 20° (OR: 2.41; 95% CI 1.13–5.16). History of previous surgery, number of instrumented vertebra, as well as postoperative SRS-Schwab modifiers and Global Alignment and Proportion score were not associated with significant effects on odds of revision. Conclusions: In a consecutive single-center cohort of patients undergoing PSO for ASD, we found an estimated incidence of revision surgery due to mechanical failure of 34% 2 years postoperatively. Fusion to the sacrum and preoperative PT > 20° were associated with elevated risks of revision. Level of evidence: Prognostic III.

KW - 3-Column osteotomy

KW - Adult spinal deformity

KW - Alignment

KW - Competing risk

KW - Cumulative incidence

KW - Global alignment and proportion

KW - Implant failure

KW - Pedicle subtraction osteotomy

KW - Revision

KW - Revision risk

KW - Scoliosis

KW - SRS-Schwab

KW - Vertebral column resection

UR - http://www.scopus.com/inward/record.url?scp=85090117446&partnerID=8YFLogxK

U2 - 10.1007/s43390-020-00195-1

DO - 10.1007/s43390-020-00195-1

M3 - Journal article

C2 - 32875546

AN - SCOPUS:85090117446

VL - 9

SP - 191

EP - 205

JO - Spine Deformity

JF - Spine Deformity

SN - 2212-134X

IS - 1

ER -